Septic complications following traumatic injury continue to be a contributing factor to morbidity and mortality. Paranasal sinusitis is being recognized as an often occult etiology of fever and sepsis in multiply injured patients. Our series of 11 patients who developed clinically important maxillary sinusitis is presented. Common features of the patients include: 1) nasal instrumentation; 2) craniofacial trauma; 3) concomitant use of steroids; and 4) severe multisystem injury (mean I.S.S., 45.5; T.S., 10.6). A high index of suspicion in patients with nasal tubes who develop unexplained fever or signs of systemic sepsis should prompt appropriate investigation of the paranasal sinuses. Removal of the tubes, antral puncture for irrigation and aspiration for microbiologic culture, topical nasal decongestants, systemic antibiotics based on sensitivity studies, and occasionally, formal surgical sinus drainage contribute to effective therapy.